Video surveillance systems are increasingly deployed within public and private institutions, such as households, commercial buildings, businesses, retail establishments, schools, hospitals and government buildings, to list a few examples. These surveillance systems are often used for a number of different tasks, such as intelligence gathering by governments and businesses, prevention or investigation of crime by law enforcement or retail establishments, and monitoring the usage of resources or structures such as buildings, bridges or roads, to list a few examples.
A number of components are common to many of these video surveillance systems. Surveillance cameras capture frames of video data and audio data for scenes of interest and encode the video and audio data into streams. The surveillance cameras then send the streams over one or more data networks, such as governmental, service provider, enterprise or home networks for recording and analysis. The data networks typically support the Internet Protocol (IP) suite of networking protocols, in one example. Network video recorders (NVR) receive the streams from the surveillance cameras and record the streams onto data storage elements for playback and analysis. Integrated or discrete video analytics systems are often included to analyze the image data. Control systems are often used to control the surveillance system and coordinate the operation of the components. Finally, video application software running on a computer system or mobile computing device allows users to configure and manage the components and access video/images.
Operators incorporate additional network video recorders into the video surveillance systems in response to an increase in the number of supported streams. Each network video recorder supports a fixed number of streams and is addressable via a separate and unique descriptor, such as an IP address. To configure recording of the streams, operators typically use the video application software to access each network video recorder by its unique address and create an association between the stream and available recording resources within the network video recorders. Each network video recorder then records the streams by storing the video streams and metadata of the streams (e.g. affixing a time stamp to the video data) to storage elements. In examples, network video recorders can store the streams to internal storage elements or to external storage elements located elsewhere within the network. Examples of external storage elements include Network Attached Storage (NAS) and directly attached storage such as a server including multiple disk drives.